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Aug. 7, 1962 R. o. PARK Re. 25,219

STOP DEVICESv FOR WELL coNDuIT 2 Sheets-Sheet 2 Original Filed Aug. 11, 1958 1 N V EN TOR. oer 0. 10A/ee BY United States Patent O1 25,219 STOP DEVICES FOR WELL CONDUIT vRobert 0. Park, Lakewood, Calif., assigner to Baker Oil The present invention relates to subsurface well bore equipment, and more particularly to stop devices adapted to be mounted on well casings, liners, tubings, and similar conduit strings, for engaging and moving other apparatus mounted on such strings through the well bore.

An object of the present invention is to provide a stop device adapted to be secured to well casings and without resort -to a welding operation, which is capable i of withstanding comparatively large longitudinally directed -forces without slipping on the casing.

Another object of the invention `is to provide a stop device of the character above indicated which is comparatively easy and economical to manufacture. As an example, most of the device can be produced on punch presses.

A further object of the invention is to provide a stop appears in the l0 casing centralizer -for illustrative purposes only,

the like As specifically illustrated,

Re. 25,219 Reissuecl Aug. 7, 1962.

ice

FIG. 8 is an isometric projection similar to FIG. 6 of a modied form of the invention;

FIG. 9 is a section of the stop device taken generally along the line 9 9 on FIG. 3.

As illustrated in the drawings, a stop device A is to be secured to a string of well casing B, or other runningin string, and is adapted to engage another apparatus C, such as a casing centralizer slidably mounted' on the casing string. The device is shown in conjunction with a it being understood that it is also useful in other relationships, being adapted for engagement with wall scratchers, cementing baskets, and other apparatus that might be slidably mounted on a casing, or similar conduit string, tr be moved longitudinally therewith through the wel bore D. i

As illustrated in the drawings, the casing centralizer C is mounted on the casing section B disposed in a wel bore D. This centralizer may take -any desired form it includes upper and lowe longitudinally spaced collars 10, 11 slidable on thecas ing section, the collars being interconnected by circum vferentially spaced outwardly bowed leaf spring member 12 welded or otherwise suitably secured thereto. Th

2.5 intermediate portions of the springs engage the wall o the well bore D and tend to `center the well casing there within B, in a known manner.

Upper and lower stop rings 13, 14 are secured in lor -gitudinally spaced relation to the upper and lower co device of the character above indicated which is easy to lars 10, 11, respectively, as by use of circumferentiall mount on a well casing or similar conduit string. More specifically, the simple expedient of striking the device at a single point with a hammer iirmly attaches the device to the casing.

An additional object of the invention is to provide stop device of the character indicated which willbe installed in a coaxial position on the well casing, the upper and lower ends of the device being normal to the axis of the well casing so that ythe device makes proper surface engagement with companion apparatus slidably mounted on the casing, such as. a casing centralizer or wall scratcher.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of 'several forms in which it 4 may be embodied. Such forms are shown in the drawings accompanying and forming part of the present specication. These -forms will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a side elevation of an apparatus mounted on a string of well casing disposed in a well bore, parts being broken away -for purposes of clarity;

FIG. 2 is a side elevational view of the stop device mounted on a casing section prior to lirm attachment of the device to the casing;

FIG. 3 is a cross section taken along the line 3-3 on FIG. 2; y v

FIG. 4 is an enlarged fragmentary section taken along the line 4 4 on FIG. 3;

FIG. 5 is an isometric projection of a stop device prior to its being mounted on a well casing;

FIG. 6 is a view similar to FIG. 5, illustrating the stop device when constricted for attachment to the well casing;

FIG. 7 is a section taken along the line 7-7 on FIG. 6;

spaced, longitudinally extending rigid bars 15 attache to both the collars and the rings by welding, or in an' other suitable manner.

The particular centralizer disclosed is of the hing a type, in which the collars =10, 11 and the rings 13, 14 a1 each made in two parts secured to one another by di: metrically opposed hinges 16. The hinges on one sic' of the device may be disconnected as by removing tl hinge pins 17 which would then allow the casing ce1 40 tralizer C to be swung to open position and place laterally Varound the casing section B. Afterwards, tl centralizer can be closed and the pins, 17 reinsertt through the hinge knuckles, :all in `a known manne The centralizer is thus slidably mounted on the casi! section.

The centralizer or centering apparatus C is movab longitudinally through the well bore upon longitudin movement of the well casing B. A stop device A is s cured to the casing section between the upper and low stop rings 13, 14 and collars 10, 11, this device bei: engageable with the inner edges 18, 19 of the rings l 14 to torce the centralizer apparatus through the wl bore. Assuming the casing B to be moved downward in the Well bore D, the stop device A engages the up; edge 19 of the lower stop ring 14 to pull the apparat C and its outwardly bowed springs 12 through the w bore and past any restrictions that might be encounter therein. On the other hand,` movement of the casi string B in an upward direction will cause the stop t 0 vice A to engage the lower edge 18 of the upper st ring 13 and pull the centering device C in an upwz direction with the casing string in the well bore.

The particular stop device illustrated in FIGS. 2 to inclusive, on the drawings, is adapted to be moun1 over an end of the casing section B and secured ther( in a desired location, after which the casing centrali: C is mounted laterally on the casing in the manner scribed above, with the stop device A disposed betwf the upper and the lower stop rings 13, 14. In the fo of stop device disclosed in FIG. 8, the centralizer other apparatus can be iirst mounted on the casing s tion, after which the stop device can be moved later-a :o appropriate assembled relation on the casing secn B between the upper and lower stop rings 13, 14 of a centralizing device, the stop device then being at* :hed to the casing section as described hereinbelow. As disclosed in FIGS. l to 7, inclusive, the stop device includes an annular member 20, such as a ring or sleeve generally cylindrial form, which has its upper and lowends 21, 22 normal to its axis. This annular member has an inside diameter greater than the outside diamr of the casing section B on which it is to be mounted :i to which it is to be secured, the annular member ving inwardly extending teeth 23, 24 adapted to bite into -grip the outer surface of the casing section. As dissed, anupper set of circumferentially spaced teeth 23 :'ormed in the interior of the annular member 20, these th facing in a downward direction and lbeing adapted grip the exterior of the well casing to prevent relative vnward movement of the annular member on the cassection. Similarly, another or lower set of circumentially spaced teeth 24 is provided, facing in an uprd direction and adapted to bite into or grip the casing tion to prevent relative upward movement of the annumember or ring with respect thereto. fhe annular member is split, and after being placed on casing section it is constricted to force its teeth 23, 24, i the exterior of the casing section B. The constricted 'ice is disposed at one side of the annular member. The in body of the annular member has upper and lower uate body portions 25, 26 on opposite sides of its t which longitudinally overlap each other. Thus, an er arcuate body portion 25 projects circumferentially n the main body portion, as in a counterclockwise di- :ion as seen in the drawings, the upper end 27 of this ly portion lying in the same plane as the upper end 21 he main body portion. The lower side 28 of thel arcubody portion is parallel to its upper end 27, being ced upwardlyby a substantial distance from the lower 22 of the annular member 20. The free end of the er arcuate body portion 25 is integral with a dependor longitudinally and downwardly extending head por- 1 29 terminating a substantial distance above the trans- :e plane in which the lower end 22 of the annular memlies. Integral with the head is a central tongue 30 ch extends from the head in a counterclockwise direcas seen in the drawings. This tongue preferably lies i central transverse plane of the `annular member 20 nal to its axis and is movable arcuately within a com- ILon central groove 31 formed in the interior of the llar member. The base 32 of the groove and the r surface 33 of the central tongue are preferably tad so as to faciitate sliding of the tongue along the i of, and within, the groove.

is to be noted that the left side 34 of the depending l 29 and the side or end 35 of the main body portion 1e annular member are spaced arcuately from one anr by -a substantial distance, and that these sides are in- :cted by the lower end 28 of the arcuate body portion defining a space adapted to receive the underlying ate body portion 26, which extends arcuately in a kwise direction, as seen in the drawings, from the r end of the main body portion. The lower arcuate r portion 26 is in overlapping relation to the upper r portion 25 and is 4actually a duplicate thereof. Thus, :nd of the lower body portion 26 merges into a longi- 1al or upwardly extending head 37 that terminates :ent the lower side 28 of the upper body portion 25. n this head, a tongue 38 projects which is adapted e received Within -a companion groove 39 within the l body portion, this tongue and groove also preferlying in the same central plane as the other tongue nd groove 31. with the base 40 of the groove tape-r- I'rom the end 35 of the main body portion in an inl direction for engagement by a companion external ice 41 on the central tongue. The lower end 42 of the lower arcuate body portion lies in the same plane normal to the axis of the annular member as the end 22 of the main body portion of the annular member, the upper end 43 of the underlying body portion 26 being disposed a substantial distance below the upper normal plane in which the end 21 of the main body lies, and adjacent to the lower end of the upper head 29 and upper central tongue 30. The side 45 of the lower head 37 and the opposite side or end 46 of the main body portion are spaced arcuately from one another for substantially the same 'distance as the side 34 of the upper head and the left side 35 of the main body to define a space with the upper endl 21 of the lower body portion into which the upper head 29 and upper tongue 30 are received. The opposed sides 34, 35 of the heads 29, 37 are also spaced from one another, which is also true of the inner ends 28, 34 of the overlapping body portions 25, 26, defining a generally rectangular opening or space 47 into which a constricting device, actuator or wedge 48 can be disposed. As shown, this actuator is generally V-shaped, having a width substantially the same as the distance between the inner ends 28, 43- of the overlapping body portions 25, 26. The outer ends of its yarms 49 are initially disposed adjacent the sides 34, 450i the heads 29, 37. The actuator 48 is retained initially in the opening 47 to prevent its loss in any suitable manner, as through use of a flexible strap 56 which maybe spot welded to one of the heads 37 Iand also to yone arm 49 of the actuator 48.

When the stop ring is in its initial position, its parts are relatively positioned as illustrated in FIGS. 2, 3, and 5. When in such position, the effective diameter across the gripping teeth 23 and 24 is slightly greater than the outside diameter of the casing section B on which the stop device is to be mounted. At this time, the tongues 30, 38 are disposed partially within their companion grooves 31, 39, there being a substantial arcuate gap 51 between the end of each body portion 25, 26 and the adjacent side 46, 35 of the main body portion of the annular member 20. At this time, also, the actuator 48y is of the V-shape disclosed, with its central portion 52 projecting laterally outwardly of the ring and with the end portions of its arms 49adjacent to or in contact with the opposed sides 34, 45 of the head portions 29, 37.

The stop device A is slipped over the end of the casing section B and is moved to the position at which it is to be secured thereto. When such position is reached, hammer blows are struck upon the central portion 52 of the actuator 48, tending to straighten the actuator in an inward direction and causing its arms 49 to shift the heads 29, 37 in opposite directions. Thus, the right head 29 is shifted in a counterclockwise direction and the left head 37 is shifted in a clockwise direction, to elect a constricting of the annular member 20 against the casing and an embedding of its teeth 23, 24 in the exterior of the casing. The parts are so proportioned that the actuator 48 can be struck repeatedly with the hammer until it is disposed in substantially the at condition shown in FIGS. 6 and 7, at which the diameter of the annular member 20 has been decreased suliicently to insure a digging in or embedding of its teeth 23, 24 in the exterior of the well casing. The flattened actuator 48 then serves as a lock or a relatively rigid bar, preventing expansion of the annular member 20 and its release from the well casing B.

During the inward hammering of the actuator 48, assurance is had that the annular member 20 does not tilt relative to the axis of the well casing, since the sliding of the central tongues 30, 38 within their companion grooves 31, 39 will maintain the upper and lower ends 21, 22 of the annular member in upper land lower central planes normal to the axis of the casing. Accordingly, the upper and lower ends of the annular member will engage the companion apparatus, such as the upper and lower stop rings 13, 14 of the casing centralizer, over substantially their full circumferential surface.

It is further to be noted that the arcuate spaces 51 that initially existed between the ends 46, 35 of the main body portion of the annular member and the opposed ends of its overlapping portions 25, 26 are such that such ends will not contact one another when the actuator 48 has 'been hammered inwardly to its fullest extent. tapered surfaces 33, 41, 32, 40 on the tongues 30, 38 and the bottoms of the grooves 31, 39" will not only insure Iappropriate relative sliding between the parts as the annular member is constricted, but will also insure that the ends of the tongues will not engage any ends of the grooves. In fact, the grooves do not have any inner ends since their tapered bottoms 32, 40 extend to the inner surface of the annular member 20.

As assurance that the actuator 48 will remain in its inward hammered position, to hold the annular member 20 constricted upon the casing, retainer portions can be struck from the overlapping body portions 25, 26 and heads 29, 37. Thus, as disclosed, a center punch or the like can be struck with a hammer to force some of the metal 60 of the head portions 29, 37 and the overlapping body portions 25, 26 inwardly of the opening 47. Such inwardly projecting metal portions 66 will not interfere with the inward hammering of the actuator 48 to a comparatively flat condition against the casing section B. Since the actuator is made of a malleable metal, the hammer blows will actually result in a deformation of some of the actuator material under the retainer` punches 60, the overlapping of the center punches 60l thus provided insuring that the actuator 48 cannot shift outwardly from the opening 47.

The stop device A illustrated is capable of withstanding large longitudinal Vforces without slipping on the casing section B. Actual tests have shown that it will withstand in excess of ten thousand pounds force on all grades of casing, including casing made from heat treated and alloy steels. Actually, in some grades of casing, the stop ring has withstood forces in excess of thirty thousand pounds. The forces mentioned above are far greater than those actually encountered in a well bore in connection with moving another apparatus, such as a casing centralizer or a wall scratcher, longitudinally in the well bore.

In addition to its ability to withstand and transmit high loads, the apparatus is very simple to construct and also economical to produce. Its various portions can -be formed on a punch press. The teeth 23, 24 can be upset from the inner wall of the annular member 20 on a punch press, and its various overlapping portions can also be formed on a punch press. This is also true of the center punch retainer portions 60 that insure against removal of the actuator `48 from its locked position between the heads 29, 37. Assurance is also had that the apparatus will be mounted square on the casing sections in View of the guiding action provided by the tongues 30, 38 within the grooves 31, 39.

The form of invention disclosed in FIG. 8 is substantially the same as the one previously described, except that the annular member 20a is made in two parts or segments 70, 71 to enable the segments to be moved laterally over the casing B and then interlocked with respect to one another. Thus, the annular member, in effeet, is provided with another split opposite its locking portion, these segments having oppositely disposed hooks 72, 73 that interlock with one another. One segment The.

between the head portions 29, 37. The striking of hammer blows upon the actuator 48 wil-l spread its arm portions 49 apart and constrict the band 20, the hooks 72, 73 on the diametrically opposite portion coupling the segments 70, 71 to one another. The locking action occurs in the same manner as described above in connection with the other for-m of the invention.

The inventor claims:

1. In a stop device adapted to be mounted on a running-in string to be disposed in a well bore: a split annular member adapted to be disposed on the running-in string, said member having overlapping portions at its split, said portions being in substantial longitudinal A alignment with each other when disposed on the running- 71 has an upwardly extending hook 73 received-within a companion recess 74 in the other segment 70 which has a downwardly extending hook 72 received within a companion recess 75 in the inst-mentioned member. The segments 7 il, 71 are placed over the casing and then moved longitudinally toward each other so that the hooks 72, 73 overlap-and interlock, with the head portions 29, 37 also longitudinally overlapping, the tongues 30, 38 being inserted in their companion grooves 31, 39. The actuator 48 will, of course, be disposed within the opening 47 in string; and means having portions engaging said overlapping portions and movable in opposite directions away from each other circumferentially of said member to force said overlapping portions away from each other to constrict said member into gripping engagement with the running-in string.

2. In a stop device adapted to be mounted on a running-in string yto be disposed in a well bore: a split annular member adapted to be disposed on the running-in string, said member having arcuately overlapping portions at its split and longitudinally overlapping portions extending longitudinally from said arcuately overlapping portions; and means engaging said longitudinally overlapping portions to force said longitudinally overlapping portions away from each other to constrict said member into gripping engagement withthe running-in string.

3. In a stop device adapted to be mounted on a running-in string to be disposed in a well bore: a split annular member adapted to be disposed on therunning-in string, said member having overlapping portions at its split; means engaging said overlapping portions and movable in a direction circumferentially of said member to force said portions away from each other to constrict said member into gripping engagement with the running-in string; and coengaging means on said member for maintaining said member coaxial with the running-in string during its constriction thereon.

4. In a stop device adapted to be mounted on a running-in string to be disposed in a well |bore: a split annular'member adapted to be disposed on the running-in string, said member having arcuately overlapping portions at its split and longitudinally overlapping portions extending longitudinally from said arcuately overlapping portions; means engaging said longitudinally overlapping portions to force said longitudinally overlapping portions away from each other to constrict said member into gripping engagement with the running-in string; and coengaging means on said member for maintaining said membei coaxial with the running-in string during its constrictior thereon.

5. In a stop device adapted to be mounted on a running-in string to be disposed in a well bore a split annular member adapted to be disposed on the running-ir string, said member having overlapping portions at it: split; means engaging said overlapping portions to forcr said portions away from each other lto [construct] con strict said member into gripping engagement with tht running-in string; a tongue secured to each overlapping portion and slidably received in a companion `groove ir the annular member to maintain said member coaxia with the running-in string during its constriction thereon 6. In a stop device adapted to be mounted on a run ning-in string to be disposed in a well bore: 4a split an nular member adapted to be disposed on the running-i1 string, said member having arcuately overlapping por tions at its split and longitudinally overlapping portion extending from said arcuately overlapping portions means engaging said longitudinally overlapping portion to force said longitudinally overlapping portions awa from each other to constrict said member intogrippin; engagement with the running-in string; and a tongue se lred to each longitudinally overlapping portion and slidaly received in a companion groove in the annular memer to maintain said member coaxial of the running-in ring during its constriction thereon.

7. In a stop device adapted ot be mounted on a inning-in string to be disposed in a well bore: a split nnular member adapted to be disposed on the runningl string, said member having overlapping portions at its lit; a deformable actuator in a plane of said member ormai to its axis and having inner ends engaging said verlapping portions and projecting in said plane from s inner ends laterally outwardly of said member, said :tuator being adapted to be forced laterally inwardly in le plane of said annular member by hammer blows to )rce said portions away from each other to constrict said lernber into gripping engagement with the running-in ring.

8. In a stop device adapted to be mounted on a runing-in string to be disposed in a Well bore: a split anular member adapted to be disposed on the running-in ring, said member having overlapping portions at its lit; a deformable actuator engaging said overlapping artions and projecting laterally outwardly of said memer, said actuator being adapted to be [force] forced inardly by hammer blows to force said portions away om each other to constrict said member into gripping lgagement wit-h the running-in string; and means on tid overlapping portions engagea'ble with said actuator r retaining said actuator in its inward position.

9. In a stop device adapted to be mounted on a run- ,ng-in [strip] string to be disposed in a well bore: a lit annular member adapted to be disposed on the runng-in string, said member having arcuately overlapng portions at its split and longitudinally overlapping )rtions extending longitudinally from said arcuately rerlapping portions; a deformable actuator engaging tid longitudinally overlapping portions and projecting terally outwardly of said member, said actuator being lapted to be forced inwardly by hammer blows to force i-d longitudinally overlapping portions way from each `her to constrict said member into gripping engagement ith the running-in string.

l0. In a stop device adapted to be mounted on a runng-in string to be disposed in a well bore: a split anilar member adapted to be disposed on the running-in ring, said member having overlapping portions at its lit; a deformable actuator engaging said overlapping )rtions and projecting laterally outwardly of said mem- :r, said actuator being adapted to be forced inwardly by :mme-r blows to force said portions away from each her to constrict said member into gripping engagement ith the running-in string; and a tongue secured to each terlapping portion and slidably received in a companion oove in the annular member to maintain said member axial of the running-in string during its constriction .ereon.

ll. In a stop device adapted to be mounted on a runng-in string to be disposed in a well bore: a split anllar member adapted to be disposed on the running-in ring, said member having overlapping portions at its llit; a deformable actuator engaging said overlapping xrtions and projecting laterally outwardly of said memzr, said actuator being adapted to be forced-inwardly by immer blows to force said portions away from each her to constrict said member into gripping engagement ith the running-in string; a tongue secured to each overpping portion and slida-bly received in a companion oove in the annular member to maintain said member axial of the running-in string during its constriction ereon; and means on said overlapping portions engagelle with said actuator for retaining said actuator in its Ward position.

12. In a stop device adapted to be mounted on a runng-in string to be disposed in a well bore: a split anllar member adapted to be disposed on the running-in string and having inner teeth therein, said member having arcuately overlapping portions at its split and longitudinally overlapping portions extending from said arcuately overlapping portions; a deformable actuator engaging said longitudinally overlapping portions and projecting laterally outwardly of said member, said actuator being adapted to -be forced inwardly Iby hammer blows to force said portions way from each other to constrict said member and cause its teeth to grip the running-in string; and a tongue secured to each longitudinally overlapping portion-and slidably received in a companion groove in the annular member to maintain said member coaxial of the running-in string during its constriction thereon.

13. In a stop device adapted to be mounted on a running-in string to be disposed in a well bore: a split annular mem-ber adapted to be disposed on the running-in string and having inner teeth therein, said member having arcuately overlapping portions at its split and longitudinally overlapping portions extending from said arcuately overlapping portions; an initially generally V- shaped :deformable actuator disposed between and engaging said longitudinally overlapping portions and projecting laterally outwardly of said member, said actuator being adapted to 'be forced inwardly toward the running-in string by hammer blows to be deformed toward a flat condition and force said longitudinally overlapping portions away from each other to constrict said member and cause its teeth to grip the running-in string; and a tongue secured to each longitudinally overlapping portion and slidably received in a companion groove in the annular member to maintain said member coaxial of the runningin string during its constriction thereon.

14. In a stop device adapted to be mounted on a running-in string to be disposed in a well bore: a split annular member adapted to be disposed on the running-in string, said member having overlapping portions at its split; and actuator means in a plane of said member normal to its [axial] axis and extending between and having inner ends engaging said overlapping portions and projecting in said plane from its inner ends laterally outwardly of said member, said actuator means being adapted to be forced laterally inwardly in the plane of said annular member to force said portions away from each other to constrict said member into gripping engagement With the running-in string.

15. In a -stop device adapted to be mounted on a running-in string to be disposed in a well bore: a -split annular member adapted to be d-isposed on the running-in string, said member having overlapping portions at its split; and actuator means in a plane of said member normal to its axis and extending between said overlapping portions and projecting in said plane laterally loutwardly of said member, said actuator means having ends engaging said overlapping portions and said actuatlolr means projecting laterally outwardly from said ends, said actuator means being adapted to be for-ced laterally inwardly in the plane of said member to force its ends circumferentially further apart and thereby force said por-tions away lfrom each other to constrict said member into gripping engagement with the running-in string.

116. In a stop ydevice adapted to be mounted on a running-in string to be disposed in -a well bore: a split annul-ar member `adapted to be disposed on the running-in string, said member having overlapping portions at its split; a deformable actuator in a plane of said member normal to its axis and engaging said overlapping portions and projecting in said plane laterally outwardly of said member, said actuator having end-s engaging said overlapping portions and said actuator means projecting late-rally outwardly from said ends, said actuator being adapted to be forced laterally inwardly in the plane of said annular member by hammer blows toward -said `annular member to force its ends circumferentially' further `apart and thereby force said portions away from each other to constrict said member into gripping engagement with the running-in string. t

17. In a stop device adapted to be mounted on a running-in string to be disposed in a well bore: a split annular member adapted to be disposed on the running-in string, said member having overlapping portions at its split; a deformable, generally V-shapedI actuator having arms secured to each other at an angle to each other and projecting laterally outwardly of said member, the inner portions ori said 4arms extending outwardly of said member from their inner ends and being in engagement with said overlapping portions, said arms being adapted to be forced inwardly by hammer blows to increase the angle between said arms and force said inner ends of said arms and said overlapping portions away from each other to constrict said member into gripping engagement with the running-in string.

18. In a stop device adapted to be mounted on a running-in string to tbe disposed in a well bore: a split annular member adapted to be disposed on the running-in string, said member having overlapping portions at its split; and actuator means having arms secured to each other at an angle to each other and projecting laterally outwardly of said member, the inner portions of said arms extending outwardly of said member from their inner ends and being in engagement with said overlapping portions, said arms being adapted to be forced laterally inwardly to 4force said inner `ends of said arms and said `overlapping portions away from each other to constrict said member into gripping engagement with the running-in string.

19. In a stop device adapted to be mounted on a running-in string to be disposed in a well bore: a split annular member adapted to be disposed `on the runningin string, said member having overlapping portions at its split; means engaging said overlapping portions and movable in a direction circumferentially of said member to force said portions away from each other to clonstrict said member into gripping engagement with the running-in string; said member including coengaging means for maintaining said member coaxial with the running-in string during its constriction thereon.

20. In a stop device adapted to be mounted on a running-in string to be disposed in a well bore: a split annular member adapted to be disposed on the runningstring, said member having overlapping portions at split, said portions being in substantial longitudinal alig ment with each other when disposed on the runningstring; a deformable, generally V-shaped actuator havi arms secured to each other at an angle to each other a. projecting laterally outwardly of said member, the inn portions of said arms extending outwardly of said met ber from their inner ends and being in engagement w; said overlapping portions, said arms being adapted to forced inwardly by hammer blows to increase the am between said arms and force said inner ends of said im arms and said overlapping portions away from each ot] to constrict said member into gripping engagement w the running-in string.

21. In a stop device adapted to be mounted on a ri ning-in string to be disposed in a well bore: a split i nular member adapted to be disposed on the running string, said member having overlapping portions at split, said portions being in substantial longitudinal ali,I ment with each other when disposed on the running string; a deformable, generally V-shaped actuator hav: arms secured to each other at an angle to each other s projecting laterally outwardly of said member, the ini portions of said arms extending outwardly of said me ber from their inner ends and being in engagement n said overlapping portions, said arms being adapted to forced inwardly by hammer blows to increase the an between said arms and force said inner ends of said in arms and said overlapping portions away from each ot to constrict said member into gripping engagement n the running-in string; said member including coengag means for maintaining said member coaxial with running-in string during its constriction thereon.

References Cited in the le of this patent or the origmal patent UNITED STATES PATENTS Germany June 24, 1I 

